2004/02/29 by G. Tkachov
Physics and Astronomy · #cond-mat.supr-con #cond-mat.mes-hall
paper · pdf · doi:10.1016/j.physc.2004.10.015
published as Physica C: Superconductivity and its applications 417 (3-4), 127-140 (2005) · 21 pages, 7 figures
arxiv created 2005/01/10 · arxiv updated 2009/12/01
Gapped excitation spectra of Andreev states are studied in one- and two-dimensional (1D and 2D) normal systems in superconducting contacts subject to a parallel magnetic field. In the ballistic regime, a specific interplay between magnetic field spin splitting and the effect of a screening supercurrent is found to preserve time-reversal symmetry for certain groups of Andreev states remaining gapped despite the presense of the magnetic field. In 1D wires such states can lead to a fractional thermal magnetoconductance equal to half of the thermal conductance quantum. In 2D systems the thermal magnetoconductance is also predicted to remain suppressed well below the normal-state value in a wide range of magnetic fields.